What is pack drill?

[bartholomew]

You won't get far at City if you keep bad company. No names, no pack drill.

Pack drill?

[andy hughes]

It's an army expression. A platoon would muster for parade, and anyone who'se uniform was not up to standrd would have his name taken, and as a punishment, have to do drill (marching) in full pack, plenty of weight to lug about - known as 'pack drill. Ideally, you would want the whole platoon to be up to standard - 'no names, no pack drill'.

In modern parlance, this transltaes to mean that you don't mention someone's name, for fear of getting them into trouble.